As substituted phenylethanolaminotetralin derivatives, compounds having gut selective sympathomimetic and anti-pollakiuria activities have been disclosed, e.g., a compound represented by the general formula: ##STR3## (wherein R.sup.a represents a hydrogen atom or an ethyl group), hydrochloride or oxalate thereof, or single optical isomers thereof; and a compound represented by the formula: ##STR4## (wherein the carbon atom marked with (R) represents a carbon atom in R configuration; and the carbon atom marked with (S) represents a carbon atom in S configuration) (cf. a published Japanese patent application (kohyo) No. Hei 6-506676 and a published Japanese patent application (kohyo) No. Hei 6-506955).
However, these compounds are .beta..sub.3 -adrenergic receptor stimulating agents having a remarkable .beta..sub.3 -adrenergic receptor stimulating effect.